Fluorinated azo dyes



United States Patent 3,086,968 FLUORINATED AZO DYES George N. Valakanas and Heinrich Hopff, Zurich, Switzerland, assignors to Staulfer Chemical Company, a corporation of Delaware No Drawing. Filed May 16, 1061, Ser. No. 110,330 6 Claims. (Cl. 260-193) This invention relates in general to a process for the preparation of fluorine-containing azoic dyestuffs.

It is an object of this invention to provide new fluorinecontaining azoic dyestuffs.

7 It is a further object of this invention to provide a method for the preparation of pigments which are of high brightness.

Other objects and advantages of this invention, if not specifically set forth, will become apparent during the course of the description which follows.

Generally, the compounds of this invention may be prepared by reacting an acetoacetofluoroanilide with a diazonium salt of a diazotized aniline.

More particularly, in the practice of this invention, an acetoacetanilide of the general formula ll U -NHCCH2 CH:

(Y)u where Y is H or --CH;,, n is 1 or 2 and A is -H or -F is prepared and reacted with a diazonium salt of a diazotized aniline material of the formula Where B, C and D are -H, -CH -OCH --NO' or F and X is -C1 or --Br. At least one of the substituents A, B, C and D represents -F. Conveniently, the diazonium compound is added as the salt, e.g. or any of the other well-known salt forms. The resulting products have the formula A Q-NHC o onN=N'- (Y). (J0 B D H3 The resulting dyes are of a green shade and possess high Example 1.'-Prep'ara ti0n of (2-Nitr0, 4-Methyl Benzolazo) Acetaa'cetic Acid (3-Methyl, 4-Fluoroavt ilide) The compound 3-rnethyl, 4-f1uoro acetoacetanilide was prepared in a 250 cc. round-bottom flask equipped with a condenser arranged for distillation. Through a separatory funnel was introduced 18. 2 g. freshly distilled acetoacetic ethyl ester, 30 cc. of xylene, and 2-3 drops of pyridine. The contents of the flask were heated to 135- 140 C. To this solution was added, drop-wise, 15 g. 2- fluoro, S-aminotoluene in 30 cc. of xylene with 5 additional drops of pyridine over a period of 5 hours in such "ice a manner that the addition rate equaled the rate at which the. solvent was distilled off. Thereafter, heating was continued for an additional two hours and additional solvent distilled off. A bright red solution was obtainedwhich was cooled to precipitate 3-methyl, 4-fiuoroacetoacetanilide. The solution was filtered and the filter cake washed with petroleum ether. The product, a fine white crystalline material, was recrystallized from Xylene; M.P. 86-87 C. A quantity of 7 g. of the B-methyl, 4-fiuord acetoacetanilide was dissolved in 100' cc. of glacial acetic acid and to this at 0 under stirring was added drop-wise over a 2-hour period 30 cc. of a diazonium salt (hydrochloride) solution of diazotized 3-nitro, 4-aminotolnene, the solution having been prepared from 6 g. of the free base. The reddish-yellow precipitate, the compound (2- nitro, 4-methyl benzolazo) acetoacetic acid (El-methyl, 4- fl'uoroanilide) was formed gradually. This was stirred for six hours at room temperature, plus an additional 12 hours in a cold-room (about 5-0 0.). Following filtration, the reddish precipitate was recrystallized from acetic acid. A golden-reddish crystalline compound was obtained which, in a 10% solution of acetic acid, dyed with a strong greenish-yellow color. Yield: 7.2 g.; 57.2% theoretical; M.P. 167-8 C.

Example 2.Preparati01v of (2-M ethyl, 5-Flw0r0 Benzolazo) Acetoacetic Acid (Z-Methyl, 5-Flu0r0anilid'e) A quantity of 10.5 g. of 2-rnethyl, S-fluoroacetoacetanilide (M.P. 86-7 C.) prepared as was the 3-methyl, 4- fluoroacetoacetanilide of Example 1 was added to the diazonium salt solution of the diazotized 2-methyl, S-fluoroaniline to yield a reddish colored precipitate which was recrystallized from acetic acid. A greenish-yellow colored crystalline compound was obtained which, in a 10% solution of acetic acid, dyed with a yellow color with green shade color. Yield: 13.5 g.; 80.5% theoretical; M.P. 179180 C.

Example 3.Preparation of (3-Flu0ro Benzolazo) Acetoacetic Acid (2-M ethyl, 5-Fluor0anilid'e) A quantity of 10 g. of 2methyl, S-fluoroacetoacetanilide was dissolved in 100 cc. of glacial acetic acid and reacted with the diazonium salt solution of diazotized mfluoroaniline (6.0 g. of free base) to yield a yellow crystalline compound (recrystallized from acetic acid). A 10% solution in acetic acid dyed with a yellow color. Yield: 11.8 g.; theoretical; M.P. 183-184 C.

Example 4.-Prepamti0n of (3-Methyl; 4-Fluor0 Ben'zolazo) Acetowcetic Acid (3-Methyl, 4-Flw0r0anilide) Example 5 .-Preparation of (3-Methyl, 4-Flu0r0 Benzolazo) Acetoacetic Acid (3-Fluoroanilide) In the fashion set forth above, 10 g. of Z-methyl, S- fluoroacetoacetanilide were dissolved in cc. glacial acetic acid and reacted with the diazoniurn salt solution of diazotized 3-rnethyl, 4-fiuoroaniline (prepared from 6.5 g. of free base) to yield a greenish-yellow crystalline compound (recrystallized from acetic acid) which, when in a 10% acetic acid solution, dyed with a greenishyellow color. Yield: 10.6 g.; 66.3% theoretical; M.P. 19S-196 C.

zolazo) Acetoacetic Acid (3-Methyl, 4-Flu0r0aniliale) v In the manner set forth above, 10 g. of 3-methy1, 4- fiuoroacetoacetanilide were dissolved in 100 cc. of glacial acetic acid and reacted with the diazonium salt solution of diazotized 3-fluoro, 4-methyl aniline (6.5 cc. of free base) to yield a yellow crystalline compound (recrystallized from acetic acid) which, when in a 10% acetic acid solution, dyed with a yellow color. Yield: 11.2 g.; 70% theoretical; M.P. 158-159 C.

I Example 7.Preparatin of (3-Fluoro, 4-Methyl Benzolazo) Acetoacetic Acid (3-Fluor0anilide) In the manner described above, g. of 3-fluoroacetoacetanilide (M.P. 926 C.) were dissolved in 100 cc. glacial acetic acid and reacted with the diazonium salt solution of diazotized 3-fluoro, 4-methyl aniline (prepared from 7 g. of free base) to yield a yellow crystalline compound (recrystallized from acetic acid). A 10% solution of acetic acid dyed with a yellow color. Yield: 11.5 g.; 70% theoretical; M.P. 218-219 C.

Example. 8.-Preparati0n 0f (Z-Methyl, 4-Nitr0 Benzolazo) Acetaacctic Acid (3-Flaor0aniliae) In the fashion described in Example 1 above, 10 g. of 3-fluoroacetoacetanilide were dissolved in 100 cc. glacial acetic acid and reacted with the diazonium salt solution of diazotized 2-methyl, 4-nitroaniline (prepared from- 8 g. of free base) to yield a reddish-yellow crystalline compound (recrystallized from acetic acid). A 10% solution of acetic acid dyed with a reddish-yellow color. Yield: 14.9 g.; 83.5% theoretical; M.P. 237-238 C.

Example 9.Preparati0n of (2-M ethyl, 4-Nitro Benzolazo) Acetoacctic Acid (3-Flaor0, 4-Methyl Anilide) 10 g. of 3-fluoro, 4-methylacetoacetaniline (M.P. 103- 104 C.) were dissolved in 100 cc. of glacial acetic acid and reacted with the diazonium salt solution of diazotized 2-methyl, 4-nitroaniline (prepared from 8 g. of free base) to yield a reddish-yellow crystalline compound (recrystallized from acetic acid). In a 10% acetic acid solution, it dyed with a yellow color. Yield: 13.3 g.; 74.8% theoretical; M.P. 208209 C.

Examle 10.Preparati0n of (Z-Methyl, 4-Nilr0 Benzolazo) Acetoacetic Acid (p-Toluidide) A quantity of 10 g. of 4-methylacetoacetanilide (M.P. 94-5 C.) was dissolved in 100 cc. of glacial acetic acid and reacted with the diazonium salt solution of diaggtized 2-methyl, 4-nitroaniline (prepared from 8.5 g. of free base) to yield a red-yellow crystalline compound (recrystallized from acetic acid). In a 10% solution of glacial acetic acid, it dyed with a reddish-yellow color. Yield: 14.2 g.; 79.0% theoretical.

Example 11 .Preparation of (Z-Methoxy, 4-Nitr0 Benzolazo) Acetoacetic Acid (3-Methyl, 4-Fla0roanilizie) Example 12.Preparati0n of (Z-Nitro, 4-Flaor0 Benzolzz0) Acet0acctic Acid (2,4-Dimethyl, o-Fluoroanilide) An additional run was made with 2,4-dimethyl, 6-

fiuoroacetoacetanilide (M.P. l60-161 C.) and 2-nitro,

4-fiuoroaniline to yield (2-nitro, 4-fluoro benzolazo) ace- 4 toacetic acid (2,4-dimethyl, 6-fluoroanilide) in a quantity of 9.8 g.; 57.7% theoretical; M.P. 199-201 C.

The foregoing runs permitted qualitative study of the effect to fluorine on Hansa-Gelb azo dyes. There was observed a red to green shift as follows:

wherein the numbers referto the products of the examples set forth above.

It has been found that the fluorine-containing azoic dyes prepared in accordance with the process set forth above display superior light fastness. 'For example, certain of them exhibit 20% greater lightfastness than the corresponding Hansa-Gelb type dyes which have been used heretofore.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appending claims.

We claim:

1. Compoundsof the general formula:

ANHC o c HN=NB 0 H where: A is selected from the class consisting of 3-methyl, 4-fluorophenyl; Z-methyl, 5-fluorophenyl; 3-fluorophenyl; S-fluoro, 4-methylphenyl; 4-methy1pheny1 and 2,4-dimethyl, 6-fiuorophenyl and B is selected from the class consisting of 2-nitro, 4-methylphenyl; Z-methyl, 5-fiuorophenyl; 3-fiuorophenyl; El-methyl, 4-fiuorophenyl; 3-fluoro, 4-methylphenyl; Z-methyl, 4-nitrophenyl; 2-methoxy, 4-nitrophenyl; and 2-nitro, 4-fluorophenyl, where at least one of A and B contains a fiuoro group.

2. The compound F NHO o OHN=NO H; 0 H8 N02 CH3 3. The compound F F I I NHO 0 OHN=N .1 0

Hi l CH3 CH3 4. The compound -NH0 0 C HN=N- O CH3 F H3 5. The compound N WHO HMM F CH3 CH3 6. The compound F C 0 (1H (11H; 3

References Cited in the file of this patent ,UNITED STATES PATENTS 2,112,764 Dahlen et a1. Mar. 29, 1938 

1. COMPOUNDS OF THE GENERAL FORMULA: 